Method of processing aluminum skimmings, screenings, slags, or analogous materials.



EAUL B. FHERSMAN, OF MILWAUKEE, WISCONSIN, ASSIGNOB, BY MESNEASSIGNMENTS, '10 WILL F. JOIBBINS, INCORPORATED, 015 AURORA, ILLINOIS, ACORPORATION METHOD OF EROGESSING ALUMINUM SKIMMINGS, SCREENINGS, SLAGS,OR ALOGOUS GB ILLINOIS,

MATERIALS.

1,229 61L Specification of Letters Patent.

No Drawing.

To all whom it may concern:

Be it known that I, PAUL B. HERSMAN, a subject of the Emperor ofAustria, residing at Milwaukee,.in the county of Milwaukee and State ofWisconsin, have invented new and useful Improvements in Methods ofProcessing Aluminum skimmings, Screenings, Slags, or AnalogousMaterials, of which the following is a full, clear, concise, and exactdescription.

This invention relates to a method of utilizing aluminum skimmings,screenings, slags or analogous materials-in such a way as to producecertain valuable and useful products. In carrying out my invention Iprefer the following procedure:

The skimmings are first separated by suitable means from the largepieces of metal occurring with them. The residual skimmings consist ofaluminum, aluminum alloys and carbid, nitrid, oxid, carbonate and other7 compounds of aluminum, small quantities of iron and copper and theircompounds, carbon and other impurities. Since the aluminum and itsalloys, left in this residual material, are present in a finely dividedcondition in which they cannot readily be separated from thenon-metallic constituents of the material, the material is best nowsubjected to the following process which effects a melting together ofthe fine metal into larger fragments and at the same time not onlyavoids the decomposition of the nitrid originally present in thematerial, but usually appreciably increases the nitrid content of thenon-metallic portion of the skimmings, etc. The skimmings, etc., fromwhich the larger fragments of metal have been removed, are intimatelymixed with'a hydrocarbon such as tar, asphaltum, petroleum oil, resinoil, or like material, the operation preferably being carried out atsuch temperature that the hydrocarbon used is freely fluid in order thatthe individual particles of the skimmings may be coated as completely aspossible with the hydrocarbon. It will be understood that thehydrocarbons when added to the skimmings may be in any form so long asthey are of such nature that they will become fluid and will thereforebecome thoroughly as a coating mixture attains the temperature at whichmixed with, and be able to act for, the skimmings before the Applicationfiled November 14, 1912. 4 Serial No. 731.347.

place. The mass is then heated in a closed retort until the mixture hasbeen brought to approximately 1,200 degrees centigrade;-

it is then quickly exposed to the air, whereupon an automatic heatingaccompanied by a considerable rise of temperature takes place, duringthe progress of which the desired reaction is completed. Magnetic ironand whatever aluminum has been fused into large particles during theprocess may then be separated by suitable means. The residue, nowpractically free from metallic aluminum or its alloys and containingusually an increased amount of available nitro en, is treated withboiling water, preferably in the presence of lime, or with otheralkaline agents to release from the mass its available nitrogen in theform of ammonia, which ammonia may then be collected in water andconcentrated in order to become a commercial product, or if preferred,it may be transformed into salts of ammonia by Well known means. Theremaining material may be treated for the recovery from it of alumi numsulfate or of other compounds of aluminum and compounds of copper whichpossess commercial value.

While the procedure described constitutes the preferred process, it isunderstood that various changes may be made in it without departing fromthe spirit of the invention.

-Thus skimmings and analogous materials which have been finely groundand then exposed to moisture and air contain very little free metal andtherefore it will in some gaining of its aluminous content and the asabove described. Other changes, also, such as making the variousprocesses continuous as will readily suggest themselves to those skilledin the art may be made without departing from the spirit of theinvention.

Having thus described my invention,,what I claim as new and desire tosecure by Letters Patent is- 1. A method of utilizing aluminum skimmmsgreenmgs, slags and the like which consists 1n mixing the same with areducing copper compounds,

pereture without access of sir to agent, heating the mixture in eeioseoi Without of iiitrogeu to W i. eiumiuum with formeii eiloiexposingit to en phere containing nit 'ogeu. v

2. A method of utilizing eiuminu things, screenings, slegs and the likeconsists in mixing the same with e W e ring agent, heating the mixturein e ciose retort Without success of air to a tempereture at whichaluminum niti ioi is foimeti and! then exposing it to the air.

- 3. A method of utilizing aluminum skir mmgs, screenings, siege antithe like which consists in mixing the same wlth e ieuucmg sccess agent,heating the mixture Without of nitrogen to e temperature of matey-1200"grade, euoi then ing it to an atmosphere containing iii methocl ofutilizing aluminum shimmings, screenings, siegs and the iike whichconsists in mixing the some with e iiquici hydrocarbon, heatingthemixture in e closed retort Without access of nitrogen to e tempemture atwhich nitrici of aluminum is formed and then exposing it to en etmosphere containing nitrogen.

5. A method of utilizing aluminum skimmiugs, screenings, siege end theiike which consists in mixing the same with at reducing agent, heatingthe mixture ilk a closed retort a tempereture such action t e usts inmixing the u in iiouici form, heating t Miiimei Jul suhsequentiyexposing e sir, th heating having vemu-M, sues yoiut aconsidertemperature results when mess is so exposed. to the air.

5 The method of utilizing eiumiuum skimming-gs, screenings, siege oreuaiogous uieteeieis, which consists in mixiugthe same 1 e hydrocerboi'quiii form, mixture in e 0% retort, suhsequentiy exposing the mess tothe sir, the heet 'ig in the cio'seoi retort having heeu carried such.point automatic heating results who: the mess is exposed to the eii,end. then finally sepereting "from the mess the Yiergei? particles ofmetai formed dieting the process.

In Witness whereof, i: have hereunto setscriheoi my name in the presenceof two Witnesses,

7 mm; it. HER$MAN.'

